Don't take a possum's age to get up to speed mate.
Playing around with several EFI cars with on-board instant and average mileage features,
I noticed that if you take say 10+ seconds to get up to 40 km/h vs. 5 seconds,
you actually start using more fuel because of running time.
There's also a big difference in how much throttle you need to BARELY maintain cruise speed,
and that just a little more that doesn't seem to accelerate the car at all but makes a little more noise
(extra manifold pressure is the noise which uses extra fuel, but no speed increase)
When you get to cruise speed, try driving like there's an egg between your foot and the throttle,
that could break at any moment.
36psi? Eeek.
What's the factory tyre pressure?
The previous owner ran 34-36 psi, but my car is rated for 28-32 psi.
I usually run 32 psi for economy, without getting too much of a jolt over bumps.
I think he might have gained about 5% in fuel economy,
but what an expense in ride harshness.
If you're very keen on high mileage,
see if you can find very skinny tyres that still have enough load rating.
Lightweight wheel and tyre combo would also help.
*and keep your current tyres for when you want to play
My Civic had 195/65R-15's for winter tyres and 205/55R-16's for summer tyres.
When I'd switch to my winter tyres, it drove like it lost 200-350lbs (1-2 adult passengers
)
They wheel and tyre combo netted only a 6 lb drop at each corner
but the narrower tyres were also a tread design for lower rolling resistance.
My winter tyres could only give me 2/3'rds the G-Force of my summers,
but what I lost in g-force, I gained at least half the difference in ease-of-acceleration.
I think I'd also gain about 5-7% in fuel economy between tanks with my winter tyres on.
I second the idea your car could be in need of tuning and/or cleaning.
My L Series for an old car, it sounded nice when I bought it,
but it sounds and runs so much better with new leads and now, 95 octane.
